Benke

The hypothesized link between mating system and relative spatial ability of the sexes can best be examined by way of a controlled comparison of male and female ranging patterns and spatial ability in species whose reproductive tactics differ but whose phylogenetic history is similar. Among the rodents, the genus Microtus includes several species whose mating systems differ dramatically, thus allowing such a comparison.

- Gaulin and FitzGerald, “Sex Differences in Spatial Ability” pg. 77

Given this polygynous pattern, the present hypothesis leads us to expect that humans would exhibit sex differences in spatial ability.

- Gaulin and FitzGerald, “Sex Differences in Spatial Ability” pg. 77

These assumptions may be unrealistic if the spatial complexity of the environment differs widely for the groups being compared… Since habitat use, and thus environmental complexity, overlaps considerably between males and females, the two sexes tend to serve as their own controls in this regard.

- Gaulin and FitzGerald, “Sex Differences in Spatial Ability” pg. 76

We take as a working assumption the idea that natural selection favors spatial ability in proportion to the amount of spatial data an animal must process in its normal movements.

- Gaulin and FitzGerald, “Sex Differences in Spatial Ability” pg. 76

This association between mating system and the relative range sizes of males and females is not without exception. For example, in some effectively polygynous lek-breeding species, males are strongly territorial and persistently localized but females forage widely. Moreover, among highly migratory species the breeding ranges of both males and females are minute compared with the size of their annual range. This annual range, which is often very similar for the two sexes, is probably more important in selecting for navigation skills, and its effects could overshadow any consequences arising out of sex differences in breeding range. Nevertheless, these exceptions do not invalidate the model developed here, but merely define its sphere of relevance and suggest criteria for the choice of species used to evaluate it.

- Gaulin and FitzGerald, “Sex Differences in Spatial Ability” pg. 76

Their analysis permits two apparent different interpretations… The first view, which stresses ontogenetic factors, suggests that males develop superior spatial ability because their wanderlust gives them more experience in processing spatial data. The second view, which is evolutionary, holds that males perform better on spatial tasks because natural selection for such cognitive skill has acted more strongly on the sex that normally ranged farther. Gray and Buffery recognize that these views present a false dichotomy, simply explaining the phenomenon at different levels.

- Gaulin and FitzGerald, “Sex Differences in Spatial Ability” pg. 75

Gray and Buffery offered a possible evolutionary explanation for the superior performance of males on spatial-learning tasks: “It seems likely that, among rodents, this male superiority is connected with the fact that, in the wild, this sex has a larger home range than does the female… (and that the) activity which is reflected in measurements of home range clearly involves the exercise of spatial ability” (Gray and Buffery 1971, p. 95)

- Gaulin and FitzGerald, “Sex Differences in Spatial Ability” pg. 75